This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Temporomandibular disorders (TMD) are a complex, heterogeneous group of clinical conditions involving pain and/or dysfunction in the muscles of mastication and related muscles of the head and neck and/or the temporomandibular joint. The localized symptoms of TMD often co-occur with the more generalized pain syndrome of fibromyalgia (FM), defined as a widespread pain, stiffness, and altered pain processing involving the locomotor system. In addition to the chronic pain, both TMD and FM usually present with other symptoms such as fatigue, mood disturbance, cognitive dysfunction, and sleep difficulty. We and others have made the case that this symptom complex is associated with significant perceived psychological or physical stress and with physiologic deficits in the stress response. In FM and TMD, altered function of stress-response systems includes the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system, and immune system. All previous studies have been limited in scope, however, focusing on either specific diagnostic group or stress exposure. Indeed, a specific patient may accumulate several diagnoses in addition to TMD and FM including chronic fatigue syndrome, irritable bowel syndrome, chronic daily headache and others. The General Hypothesis is that "individuals with FM and TMD can overlap significantly with respect to symptoms and stress physiologic phenotypes (e.g., salivary cortisol, heart-rate variability). The symptoms, rather than diagnostic group, are expected to correlate with specific neuroendocrine profile. We will recruit individuals from the University of Kentucky outpatient rheumatology and orofacial pain clinics and the Kentucky Women's Health Registry. Subjects will be classified into 4 groups (FM, TMD, FM and TMD and healthy matched controls). The specific aims to be tested are: Specific Aim 1: Examine the relationship between FM and TMD and the presence and severity of symptom profiles to determine the relationship between diagnostic group and symptoms;Specific Aim 2: Determine the association between psychosocial stress and distress on symptoms, diagnostic groups (TMD, FM, TMD and FM, and healthy matched controls) and stress physiology;and, Specific Aim 3: Compare the stress physiology phenotypes of four subject groups: (1) TMD, (2) FM, (3) TMD and FM and (4) healthy age-matched controls.